mirror of
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2025-09-04 20:19:47 +08:00
32e2eae23f
Most of the driver-specific documentation is meant to help users of the media subsystem. Move them to the admin-guide. It should be noticed, however, that several of those files are outdated and will require further work in order to make them useful again. Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
162 lines
5.6 KiB
ReStructuredText
162 lines
5.6 KiB
ReStructuredText
.. SPDX-License-Identifier: GPL-2.0
|
|
|
|
i.MX7 Video Capture Driver
|
|
==========================
|
|
|
|
Introduction
|
|
------------
|
|
|
|
The i.MX7 contrary to the i.MX5/6 family does not contain an Image Processing
|
|
Unit (IPU); because of that the capabilities to perform operations or
|
|
manipulation of the capture frames are less feature rich.
|
|
|
|
For image capture the i.MX7 has three units:
|
|
- CMOS Sensor Interface (CSI)
|
|
- Video Multiplexer
|
|
- MIPI CSI-2 Receiver
|
|
|
|
.. code-block:: none
|
|
|
|
MIPI Camera Input ---> MIPI CSI-2 --- > |\
|
|
| \
|
|
| \
|
|
| M |
|
|
| U | ------> CSI ---> Capture
|
|
| X |
|
|
| /
|
|
Parallel Camera Input ----------------> | /
|
|
|/
|
|
|
|
For additional information, please refer to the latest versions of the i.MX7
|
|
reference manual [#f1]_.
|
|
|
|
Entities
|
|
--------
|
|
|
|
imx7-mipi-csi2
|
|
--------------
|
|
|
|
This is the MIPI CSI-2 receiver entity. It has one sink pad to receive the pixel
|
|
data from MIPI CSI-2 camera sensor. It has one source pad, corresponding to the
|
|
virtual channel 0. This module is compliant to previous version of Samsung
|
|
D-phy, and supports two D-PHY Rx Data lanes.
|
|
|
|
csi-mux
|
|
-------
|
|
|
|
This is the video multiplexer. It has two sink pads to select from either camera
|
|
sensor with a parallel interface or from MIPI CSI-2 virtual channel 0. It has
|
|
a single source pad that routes to the CSI.
|
|
|
|
csi
|
|
---
|
|
|
|
The CSI enables the chip to connect directly to external CMOS image sensor. CSI
|
|
can interface directly with Parallel and MIPI CSI-2 buses. It has 256 x 64 FIFO
|
|
to store received image pixel data and embedded DMA controllers to transfer data
|
|
from the FIFO through AHB bus.
|
|
|
|
This entity has one sink pad that receives from the csi-mux entity and a single
|
|
source pad that routes video frames directly to memory buffers. This pad is
|
|
routed to a capture device node.
|
|
|
|
Usage Notes
|
|
-----------
|
|
|
|
To aid in configuration and for backward compatibility with V4L2 applications
|
|
that access controls only from video device nodes, the capture device interfaces
|
|
inherit controls from the active entities in the current pipeline, so controls
|
|
can be accessed either directly from the subdev or from the active capture
|
|
device interface. For example, the sensor controls are available either from the
|
|
sensor subdevs or from the active capture device.
|
|
|
|
Warp7 with OV2680
|
|
-----------------
|
|
|
|
On this platform an OV2680 MIPI CSI-2 module is connected to the internal MIPI
|
|
CSI-2 receiver. The following example configures a video capture pipeline with
|
|
an output of 800x600, and BGGR 10 bit bayer format:
|
|
|
|
.. code-block:: none
|
|
|
|
# Setup links
|
|
media-ctl -l "'ov2680 1-0036':0 -> 'imx7-mipi-csis.0':0[1]"
|
|
media-ctl -l "'imx7-mipi-csis.0':1 -> 'csi-mux':1[1]"
|
|
media-ctl -l "'csi-mux':2 -> 'csi':0[1]"
|
|
media-ctl -l "'csi':1 -> 'csi capture':0[1]"
|
|
|
|
# Configure pads for pipeline
|
|
media-ctl -V "'ov2680 1-0036':0 [fmt:SBGGR10_1X10/800x600 field:none]"
|
|
media-ctl -V "'csi-mux':1 [fmt:SBGGR10_1X10/800x600 field:none]"
|
|
media-ctl -V "'csi-mux':2 [fmt:SBGGR10_1X10/800x600 field:none]"
|
|
media-ctl -V "'imx7-mipi-csis.0':0 [fmt:SBGGR10_1X10/800x600 field:none]"
|
|
media-ctl -V "'csi':0 [fmt:SBGGR10_1X10/800x600 field:none]"
|
|
|
|
After this streaming can start. The v4l2-ctl tool can be used to select any of
|
|
the resolutions supported by the sensor.
|
|
|
|
.. code-block:: none
|
|
|
|
# media-ctl -p
|
|
Media controller API version 5.2.0
|
|
|
|
Media device information
|
|
------------------------
|
|
driver imx7-csi
|
|
model imx-media
|
|
serial
|
|
bus info
|
|
hw revision 0x0
|
|
driver version 5.2.0
|
|
|
|
Device topology
|
|
- entity 1: csi (2 pads, 2 links)
|
|
type V4L2 subdev subtype Unknown flags 0
|
|
device node name /dev/v4l-subdev0
|
|
pad0: Sink
|
|
[fmt:SBGGR10_1X10/800x600 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:full-range]
|
|
<- "csi-mux":2 [ENABLED]
|
|
pad1: Source
|
|
[fmt:SBGGR10_1X10/800x600 field:none colorspace:srgb xfer:srgb ycbcr:601 quantization:full-range]
|
|
-> "csi capture":0 [ENABLED]
|
|
|
|
- entity 4: csi capture (1 pad, 1 link)
|
|
type Node subtype V4L flags 0
|
|
device node name /dev/video0
|
|
pad0: Sink
|
|
<- "csi":1 [ENABLED]
|
|
|
|
- entity 10: csi-mux (3 pads, 2 links)
|
|
type V4L2 subdev subtype Unknown flags 0
|
|
device node name /dev/v4l-subdev1
|
|
pad0: Sink
|
|
[fmt:Y8_1X8/1x1 field:none]
|
|
pad1: Sink
|
|
[fmt:SBGGR10_1X10/800x600 field:none]
|
|
<- "imx7-mipi-csis.0":1 [ENABLED]
|
|
pad2: Source
|
|
[fmt:SBGGR10_1X10/800x600 field:none]
|
|
-> "csi":0 [ENABLED]
|
|
|
|
- entity 14: imx7-mipi-csis.0 (2 pads, 2 links)
|
|
type V4L2 subdev subtype Unknown flags 0
|
|
device node name /dev/v4l-subdev2
|
|
pad0: Sink
|
|
[fmt:SBGGR10_1X10/800x600 field:none]
|
|
<- "ov2680 1-0036":0 [ENABLED]
|
|
pad1: Source
|
|
[fmt:SBGGR10_1X10/800x600 field:none]
|
|
-> "csi-mux":1 [ENABLED]
|
|
|
|
- entity 17: ov2680 1-0036 (1 pad, 1 link)
|
|
type V4L2 subdev subtype Sensor flags 0
|
|
device node name /dev/v4l-subdev3
|
|
pad0: Source
|
|
[fmt:SBGGR10_1X10/800x600@1/30 field:none colorspace:srgb]
|
|
-> "imx7-mipi-csis.0":0 [ENABLED]
|
|
|
|
References
|
|
----------
|
|
|
|
.. [#f1] https://www.nxp.com/docs/en/reference-manual/IMX7SRM.pdf
|